Entanglement evolution in multipartite cavity-reservoir systems under local unitary operations

TL;DR

This paper studies how entanglement evolves in a multipartite cavity-reservoir system under local unitary operations, revealing a single parameter governs the dynamics and introducing new measures for multipartite entanglement analysis.

Contribution

It introduces a unified framework for analyzing bipartite and multipartite entanglement evolution, including new entanglement measures and the effect of local operations.

Findings

Entanglement dynamics depend on a single parameter under local unitaries.

Cavity photon entanglement correlates with reservoir entanglement.

Local operations can delay or advance entanglement transitions.

Abstract

We analyze the entanglement evolution of two cavity photons being affected by the dissipation of two individual reservoirs. Under an arbitrary local unitary operation on the initial state, it is shown that there is only one parameter which changes the entanglement dynamics. For the bipartite subsystems, we show that the entanglement of the cavity photons is correlated with that of the reservoirs, although the local operation can delay the time at which the photon entanglement disappears and advance the time at which the reservoir entanglement appears. Furthermore, via a new defined four-qubit entanglement measure and two three-qubit entanglement measures, we study the multipartite entanglement evolution in the composite system, which allows us to analyze quantitatively both bipartite and multipartite entanglement within a unified framework. In addition, we also discuss the entanglement evolution with an arbitrary initial state.